Illumination optical units for EUV projection lithography for illuminating an object field with illumination light, wherein an object to be imaged is arrangeable in the object field, are known from U.S. Pat. No. 6,507,440 B1, U.S. Pat. No. 6,438,199 B1, US 2011/0318696 A1, US 2011/0001947 A1 and WO 2012/034995 A2.